Originally known as Harry O'Brien, the Brazilian born Lumumba debuted in 2005 and played in the 2010Collingwood premiership team.

In 2014 he joined Melbourne as part of a three-way trade which sent Mitch Clark to Geelong and Travis Varcoe to the Pies, and played 19 games in his first season with the club. His second year was ruined by a concussion suffered early in the season and he was restricted to five games. He retired in December 2016, but remained on Melbourne's 2017 list.